Touch screen devices, and in particular touch screen cell phones, have grown in popularity over the past few years because they enable a user to interact directly with content displayed on the display, rather than through an intermediary, such as a hardware QWERTY keyboard. Touch screen devices generally comprise software keys (e.g., icons displayed on the display) and touch sensors, integrated into the display, that detect the presence and location of a user's touch within the display. Software correlates the location of the touch to an icon displayed in the vicinity of the touch to determine what a user intended to select.
Several manufacturers of touch screen devices have opted to eliminate or substantially reduce the number of hardware keys integrated into touch screen devices. Instead, manufacturers create software keys that may be selectively displayed on the screen (e.g., when user input is desired). There are several advantages to reducing the number of hardware keys, particularly for manufacturers of cell phones and other small handheld devices. For example, manufacturers may be able to offer devices that are more sleek (e.g., relative to bulkier devices that may have a full, hardware QWERTY keyboard) and/or have a larger screen (e.g., because available space is not consumed by hardware keys). Manufacturers may also reduce the cost of producing the device because less hardware components are needed. Additionally, consumers may benefit because the cost of the device may be cheaper and the software keys may offer more flexibility with regards to key arrangement (e.g., users may switch between a numerical keyboard, a full QWERTY keyboard, a compact QWERTY, and since they generally comprise icons on a touch sensitive screen, software keys may be added, subtracted, resized, rearranged, reconfigured with different functionality, etc.) than hardware keys. Also, there may be fewer software key failures relative to hardware key failures (e.g., buttons becoming corroded and/or stuck), thus prolonging the useful life of the device.
While there are numerous benefits to software keys, there are also several disadvantages that have discouraged some consumers from purchasing touch screen devices that predominately rely on software keys for user input. For example, the development of software keys lags behind hardware keys. Therefore, touch screen devices still have some difficulty in determining the precise location of the user's touch on the display (e.g., causing a key other than the user's intended key to be selected). Additionally users that use the device primarily for text messaging and/or email, such as enterprise users, tend to prefer hardware keys that provide haptic feedback over software keys that do not provide a sense of touch. Some users also prefer hardware keys because software keys take up valuable display space that could display other content, such as a larger portion of an email the user is typing, for example. Therefore, the potential markets for touch screen devices that utilize software keys may be limited.